Abstract
Objectives:
The only human Lyme disease vaccine of LYMErix was voluntarily removed from the market in the United States in 2002 for a number of reasons. A new human Lyme disease vaccine is currently being developed. We would like any future approved human Lyme disease vaccine to be of interest and marketable to consumers.
Methods:
We surveyed 714 participants to determine variables associated with intentions to receive a Lyme disease vaccine. Predictor variables included demographics, protection motivational theory, Lyme disease knowledge, Lyme disease preventive behaviors, beliefs and perceived health.
Results:
We found in multivariate linear regression analyses that Asian/Asian American race/ethnicity (p < 0.001), South Asian race/ethnicity (p = 0.01) and coping appraisal variables of response efficacy (p < 0.001) and self-efficacy (p < 0.001) were each significantly associated with increased intentions. The belief that vaccines are typically not safe was significantly associated with decreased intentions (p = 0.03).
Conclusions:
Asian/Asian American and South Asian race/ethnicities have a strong interest in receiving a Lyme disease vaccine. Although pharmaceutical companies may benefit by advertising a Lyme disease vaccine to Asian/Asian Americans and South Asians, marketers need to address and use approaches to interest those from other race/ethnicities. Also, marketers need to address the erroneous belief that vaccines are typically not safe in order to interest those with such beliefs to use a Lyme disease vaccine.
Introduction
Lyme disease is caused by the bacterial pathogen Borrelia burgdorferi which is transmitted by a tick bite. Lyme disease can have abnormal cardiac, dermatologic, neurologic and rheumatologic symptoms [Centers for Disease Control and Prevention, 2015]. In the United States, there are approximately 300,000 new cases annually of Lyme disease, with these cases typically occurring in the northeast and midwest [Centers for Disease Control and Prevention, 2013].
The first Lyme disease vaccine named LYMErix was approved in 1998 by the US Food and Drug Administration (FDA) for use in the United States. Although the vaccine was initially popular with physicians regarding the efficacy of the vaccine, there were reports of adverse side effects of arthritis due to the OspA serotype of the vaccine. Some researchers proposed a molecular mimicry model of the vaccine causing treatment-resistant Lyme-induced arthritis and other researchers proposed that the vaccine induced autoimmune arthritis. This resulted in extensive media coverage about these concerns and also websites reporting about vaccine victims. Antivaccine groups formed specifically to promote the withdrawal of the Lyme vaccine from the market. Also, a class action lawsuit initiated against the vaccine manufacturer accused the manufacture of concealing evidence of the harmfulness of the vaccine [Poland, 2011]. In 2001, the FDA re-examined the clinical trial data and did not find that the data indicated a side effect of arthritis. Also, in 2001 the Vaccine Adverse Events Reporting System (VAERS) did not indicate any greater frequency of arthritis symptoms between vaccinated and nonvaccinated individuals [Nigrovic and Thompson, 2007]. However, the reported molecular mimicry and autoimmune responses, antivaccine sentiment, class action lawsuit, and the necessary complicated vaccine administration schedule resulted in decreased demand for the vaccine from both physicians and the public. In 2002, the manufacturer voluntarily removed LYMErix from the market [Poland, 2011].
Vaccines are an important milestone for improved public health and ideally contribute toward strong declines in both the incidence and mortality for diseases prevented by vaccination. However, despite these known benefits, there still remains a group of individuals who are opposed to vaccines [Kata, 2012]. There has always been opposition to vaccination and every time a new vaccine is introduced, there is always some level of fear and mistrust by the public [Poland and Jacobson, 2011]. For effective vaccines, inadequate use of the vaccine can become a public health issue, as declining vaccination rates at the population level could lead to an increase in morbidity and mortality from diseases that are vaccine preventable. The coverage of some vaccines will no longer be adequate to confer herd immunity, which could otherwise protect the immune compromised and children too young to immunize [Ropeik, 2013]. The Internet has an important role in facilitating and transmitting antivaccine beliefs with the creation and sharing of user-generated content on websites and through social media [Kata, 2012]. Modern anxiety about vaccines is related to a disproven and retracted article claiming that the measles–mumps–rubella (MMR) vaccine causes autism [Poland, 2011]. There are many other reasons cited by those opposed to vaccination, including that vaccines are unnatural, science was wrong beforehand and that pharmaceutical companies are advocating their use for their own profitable agenda [Kata, 2012].
There is very limited literature on predictors of use for a human Lyme disease vaccine. We are aware of only one study where those who were considered at risk for Lyme disease were offered an approved Lyme disease vaccine. There were no demographic differences between those who chose to be vaccinated versus those not vaccinated. Those who were vaccinated indicated multiple reasons for vaccination with the main reason a risk of tick exposure. Those who declined vaccination cited reasons of vaccine safety, vaccine novelty and vaccine efficacy [Nolan and Mauer, 2006].
An approach for an effective human Lyme disease vaccine was revisited. A European phase I/II Lyme disease vaccine trial showed promising results where their vaccine protected against Lyme disease. Not only did their vaccine show increased antibodies for the OspA 1 serotype previously included in the discontinued LYMErix vaccine, but their vaccine also showed increased antibodies for five additional serotypes of OspA serotypes 2–6, increasing the protective capabilities against a larger variety of disease causing Borrelia species. This vaccine avoids the earlier proposed concerns of the discontinued LYMErix vaccine by replacing the OspA-1 epitope with the corresponding OspA-2 sequence [Wressnigg et al. 2013]. We are optimistic that this new Lyme disease vaccine will eventually be approved for human use. However, we want to prevent another marketing failure of having an effective human Lyme disease vaccine removed. In this cross-sectional study we analyze variables associated with human Lyme disease vaccine use. We analyze predictors from a number of areas of demographics, knowledge, preventive behavior, health topics and protection motivation theory [Norman et al. 2005] for intentions to receive a human Lyme disease vaccine.
Material and methods
Participants
We approached 757 college students to participate in our anonymous survey. All college students were eligible to participate. The survey was administered at a public college located in New York City. Of those approached, 21 refused to participate. The response rate was 97.2% from the 736 completed surveys [(736/757) × 100%]. We excluded 22 individuals above the age of 36 in order to maintain a more conventional college-aged group. Data were analyzed from 714 participants. The study was approved by the college’s Human Research Protections program and was ethically conducted according to the guidelines of the Declaration of Helsinki. All participants provided informed consent. Participants were surveyed from September through October 2014.
Participants completed the anonymous surveys in classrooms. The survey began with an introductory description on the current status of lack of an available human Lyme disease vaccine. Additionally, we informed participants about the European phase I/II study published in August 2013 that showed very strong promise for a potentially new vaccine for preventing individuals from becoming infected with Lyme disease. We asked participants to respond and assume that this new vaccine for Lyme disease completed a successful phase III clinical trial and was approved by the FDA.
Measures
Protection motivational theory
Response efficacy
The response efficacy scale consists of three items. Items were slightly modified from a previous article about the human papilloma virus (HPV) vaccine [Gainforth et al. 2012]. A Likert-style scale was used to measure all the items with a range from 1 = strongly disagree to 7 = strongly agree. A sample item is: ‘Being vaccinated to prevent becoming infected with Lyme disease leads to feelings of relief’. The total score was calculated by adding all three items. Greater scores indicate greater response efficacy. Cronbach alpha reliability in this sample is 0.87.
Self-efficacy
The self-efficacy scale consists of three items. Items were slightly modified from a previous article about the HPV vaccine [Gainforth et al. 2012]. A Likert-style scale was used to measure all the items with a range from 1 = strongly disagree to 7 = strongly agree for 2 of the items and 1 = extremely difficult to 7 = extremely easy for one of the items. A sample item for the extremely difficult/extremely easy measurement is: ‘For me, getting vaccinated to prevent becoming infected with Lyme disease will be’. The total score was calculated by adding all three items. Greater scores indicate greater self-efficacy. Cronbach alpha reliability in this sample is 0.83.
Response cost
The response cost scale consists of four items. Items were slightly modified from a previous article about the HPV vaccine [Gainforth et al. 2012]. A Likert-style scale was used to measure all the items with a range from 1 = strongly disagree to 7 = strongly agree. A sample item is: ‘Being vaccinated to prevent becoming infected with Lyme disease would be inconvenient for me’. The total score was calculated by adding all three items. Greater scores indicate greater response cost. Cronbach alpha reliability in this sample is 0.73.
Perceived severity
Perceived severity consists of two items. Items were slightly modified from a previous article about Lyme disease [Beaujean et al. 2013]. A Likert-style scale was used to measure all the items with a range from 1 = strongly disagree to 7 = strongly agree. A sample item is: ‘Lyme disease is a serious disease’. Due to poor Cronbach alpha reliability, each item was analyzed separately.
Perceived vulnerability
Perceived vulnerability consists of two items. Items were slightly modified from a previous article about Lyme disease [Beaujean et al. 2013]. A Likert-style scale was used to measure all the items with a range from 1 = strongly disagree to 7 = strongly agree. A sample item is: ‘If I do not take preventive measures, I am susceptible to getting Lyme disease’. Due to poor Cronbach alpha reliability, each item was analyzed separately.
Fear
The fear scale consists of two items. One item was slightly modified from a previous article about Lyme disease [Beaujean et al. 2013]. Another item was an original item. A Likert-style scale was used to measure all the items with a range from 1 = strongly disagree to 7 = strongly agree. A sample item is: ‘I am worried about getting Lyme disease’. The total score was calculated by adding all two items. Greater scores indicate greater fear. Cronbach alpha reliability in this sample is 0.89.
Rewards
The reward items consists of two items, one intrinsic and the other extrinsic. These were original items created for this survey. A Likert-style scale was used to measure all the items with a range from 1 = strongly disagree to 7 = strongly agree. The item for intrinsic reward is: ‘After receiving a vaccine to prevent becoming infected with Lyme disease, I will not have to worry about becoming infected with Lyme disease’. The item for extrinsic reward is: ‘After receiving a vaccine to prevent becoming infected with Lyme disease, my family and/or friends will not have to worry about my becoming infected with Lyme disease’. Greater scores indicate greater rewards.
Demographics
Age (years), sex (man, woman) and race/ethnicity (White, African American, Hispanic, Asian, South Asian, or other) were measured.
Knowledge
Knowledge related to Lyme disease variables are composed of five true or false questions. Four items were obtained from a previous article [Beaujean et al. 2013]. The knowledge question, ‘Ticks mostly fall out of trees’, was reverse coded for the correct answer of false. Other knowledge questions are ‘People can get Lyme disease after a tick bite’, ‘The chance for tick bites is higher during the summer than the winter’ and ‘Using insect repellent on skin can protect against tick bites’. Also, based upon information available from the Centers for Disease Control and Prevention (CDC) website [Centers for Disease Control and Prevention, 2014], we created the question of: ‘The insect that causes Lyme disease is typically as large as an adult common housefly’.
Behavior
The behavior variables consist of five preventive behaviors that an individual may partake in to prevent and/or decrease the likelihood of becoming infected with Lyme disease. These items were obtained from a previous article [Gould et al. 2008]. Each corresponding behavior was accompanied by a choice of either ‘never’, ‘sometimes’ or ‘always.’ An example of a behavior variable is: ‘Perform tick checks after being outdoors’.
Miscellaneous
These were six original items created for this survey. These items included questions with ‘yes’ or ‘no’ responses that were aimed to get additional information about certain behaviors, beliefs and history related to Lyme disease. These items were: ‘In general, vaccines are typically not safe’, ‘I typically spend a lot of time outdoors’, ‘Before participating in this survey, have you ever heard of Lyme disease?’, ‘Have you ever been diagnosed with Lyme disease?’, Do you know someone who was diagnosed with Lyme disease?’ and ‘Have you ever had a tick bite?’.
Perceived health
Participants were asked to describe their overall health as the following: ‘excellent’, ‘very good’, ‘good’, ‘fair’ and ‘poor’. The choices of ‘fair’ and ‘poor’ were combined since there were relatively few individuals that described themselves in poor health and these choices would not be suitable as a subset on their own.
Intentions
The intentions scale consists of three items. These items were created based upon the guidelines of the manual for measuring the Theory of Planned Behavior [Francis et al. 2004]. A Likert-style scale was used to measure all the items with a range from 1 = strongly disagree to 7 = strongly agree. A sample item is: ‘I expect to get vaccinated to prevent becoming infected with Lyme disease’. The total score was calculated by adding all three items. Greater scores indicate greater intentions. Cronbach alpha reliability in this sample is 0.93.
Statistical analysis
Univariate linear regression analysis studied the outcome of intentions to receive a Lyme disease vaccine. Predictors included protection motivational theory variables, demographics, knowledge, behaviors for Lyme disease prevention, miscellaneous variables and perceived health. Multivariate linear regression analysis studied the outcome of intention to use a Lyme disease vaccine and only included variables that were statistically significant with the univariate linear regression analysis. Also, a separate multivariate linear regression analysis was repeated for the subset of individuals that previously heard of Lyme disease. All analyses used IBM SPSS version 20 [IBM Corporation, 2011]. All p values were two-sided.
Results
Table 1 describes the variables. With regard to knowledge, more than three-quarters correctly answered that one can get Lyme disease after a tick bite and that the chances for tick bites are higher in the summer than winter. However, less than half correctly answered that the insect that causes Lyme disease is typically as large as an adult common housefly. With regard to behaviors, most did not perform tick checks after being outdoors or tuck pant legs into socks. Almost half sometimes used insect repellant on skin and/or clothing when outdoors. Almost half sometimes wore long pants in wooded or brushy areas. More than half sometimes avoided wooded areas. With regard to the miscellaneous variables, less than one-fifth believed that vaccines were not safe. Slightly more than half spent a lot of time outdoors and slightly more than half had heard of Lyme disease prior to participating in this survey. Less than 2% reported ever being diagnosed with Lyme disease. Less than one-fifth knew someone diagnosed with Lyme disease and less than one-fifth ever reported having a tick bite. With regard to perceived health, less than 5% had fair/poor health.
Descriptive statistics of 714 surveyed college students.
SD, standard deviation.
Table 2 shows linear regression analyses for intentions to obtain a vaccine for Lyme disease. In the univariate analyses, for demographics, younger age, those of Asian/Asian American and South Asian race/ethnicity were significantly associated with increased intentions. With regard to the protection motivational theory variables, increased response efficacy, increased self-efficacy, increased rewards intrinsic, increased rewards extrinsic, increased perceived severity, increased perceived vulnerability, increased fear and decreased response cost were all significantly associated with increased intentions. None of the knowledge variables were significantly associated with intentions. With regard to behavior, those who responded always to ‘Use insect repellent on skin and/or clothing when outdoors’ were significantly associated with increased intentions. With regard to miscellaneous variables, individuals that answered ‘yes’ to the item ‘Spend a lot of time outdoors’ were significantly associated with increased intentions. Individuals that answered ‘yes’ to item ‘Had a tick bite’ and ‘Believe vaccines are typically not safe’ were significantly associated with decreased intentions. Sex and perceived health were not significantly associated with intentions. In the multivariate analyses, the demographic variable of race/ethnicity for Asian/Asian American, South Asian and Other were significantly associated with increased intentions. With regard to the protection motivational theory variables, increased response efficacy, increased self-efficacy, decreased response cost, increased perceived severity and increased fear were significantly associated with increased intentions. With regard to behavior, those who responded always to, ‘Use insect repellent on skin and/or clothing when outdoors’ were significantly associated with increased intentions. With regard to miscellaneous variables, individuals who answered ‘yes’ to the item ‘Believe vaccines are typically not safe’ were significantly associated with decreased intentions.
Linear regression analysis for intentions to obtain a vaccine for Lyme disease.
B, unstandardized beta; SE, standard error.
Table 3 shows multivariate regression analysis for intentions to obtain a vaccine for Lyme disease in the subset of individuals who had previously heard of Lyme disease. With regard to the demographic variable of race/ethnicity, only Asian/Asian American and Other were significantly associated with increased intentions. With regard to the protection motivational theory variables, increased response efficacy, increased self-efficacy, decreased response cost and increased fear were significantly associated with increased intention. With regard to the behavior variables, only individuals that responded ‘always’ to the item of ‘Use insect repellent on skin and/or clothing when outdoors’ were significantly associated with increased intentions. With regard to miscellaneous variables, individuals who answered ‘yes’ to the item ‘Believe vaccines are typically not safe’ were significantly associated with decreased intentions.
Linear regression analysis for intentions to obtain a vaccine for Lyme disease in the subset of individuals who previously heard of Lyme disease.
B, unstandardized beta; SE, standard error.
Discussion
Only slightly more than half knew that insect repellent on skin can protect against tick bites. Also, more than two-thirds never performed tick checks after being outdoors. Asian/Asian Americans, South Asian and Other were significantly associated with increased intention to obtain a Lyme disease vaccine. With regard to our theoretical framework of protection motivational theory, the coping appraisal variables were significantly associated with increased intention to obtain a Lyme disease vaccine, while the threat appraisal variables were not consistently associated with increased intentions. None of the knowledge or behavior variables were significantly associated with intention to obtain a Lyme disease vaccine. Also, only one of the beliefs that vaccines are typically not safe was associated with decreased intention to obtain a Lyme disease vaccine.
We found that Asian/Asian Americans, South Asian and Other were significantly associated with increased intention to obtain a Lyme disease vaccine. We are not aware of any literature showing greater interest for Asian/Asian Americans and South Asians than other racial/ethnic groups for interest in obtaining a Lyme disease vaccine. There is literature reporting that among those residing in the UK that Asians have much greater percentages than Whites (50.0% versus 21.4%) for obtaining for their children the second dose of the MMR vaccine [Brown et al. 2011]. Our findings show a similar pattern of greater interest among Asian/Asian Americans and South Asian than whites for interest in a Lyme disease vaccine. We are not aware of any reasons for this greater interest in the Lyme disease vaccine and future research would be useful to understand the greater interest among Asian/Asian Americans and South Asians. We did not find any relationship of either age or sex with intention to obtain a Lyme disease vaccine. This is consistent with the findings of the previous one study on those who were considered at risk for Lyme disease and were offered an approved Lyme disease vaccine that there were no age or sex differences [Nolan and Mauer, 2006].
With regard to our theoretical framework of protection motivational theory, all of the coping appraisal variables (increased response efficacy, increased self-efficacy, decreased response cost) were significantly associated with intentions to obtain a Lyme disease vaccine. However, for threat appraisal variables, rewards and vulnerability were not significantly associated with intentions. Also, in the general sample, perceived severity was significantly associated with increased intentions, while in the subset of those who had previously heard of Lyme disease, perceived severity was not significantly associated with increased intentions. Only the threat appraisal intervening variable of fear was significantly associated with increased intentions. A review article on vaccine use for influenza found that the variables for protection motivational theory for both coping appraisal and threat appraisal were significantly associated with intentions [Bish et al. 2011]. Also, another study found that fear was associated with increased health protective behaviors to prevent avian influenza [Raude and Setbon, 2011]. Our lack of findings for threat appraisal for intentions to use a Lyme disease vaccine differs from this previous research. It is possible that our urban sample does not perceive Lyme disease as a threat relevant to them and this is why the threat appraisal variables were not significantly associated with increased intentions.
We found that knowledge about Lyme disease was not associated with intentions to obtain a Lyme disease vaccine. A review article found that knowledge of risk factors for influenza was in most studies associated with increased intentions to obtain the influenza vaccine [Chapman and Coups, 1999]. Our study differs from the pattern seen for the influenza vaccine. It is possible that our urban sample, despite being generally knowledgeable about Lyme disease, does not perceive Lyme disease as a threat relevant to them and this is why knowledge did not have any association with intentions.
Engagement in Lyme disease preventive behaviors was low, especially for performing tick checks after being outdoors. Also, we found that use of Lyme disease preventive behaviors was generally not associated with increased intentions to obtain a Lyme disease vaccine. Previous research reports that people do not engage in preventive behaviors for Lyme disease due to reasons of inconvenience, too much of a hassle, or disliking placing insect repellant on their skin [Beaujean et al. 2013]. The relatively lower interest in performing preventive behaviors on a regular basis is consistent with a lack of association for intentions to obtain a Lyme disease vaccine.
We found that the attitude that vaccines are not safe was associated with decreased intentions to receive a Lyme disease vaccine. Previous research with a number of vaccines including the influenza vaccine [Bish et al. 2011], the HPV vaccine [Brewer and Fazekas, 2007] and the MMR vaccine [Pearce et al. 2008] all found that the attitude that vaccines are not safe was associated with decreased receipt of the vaccine. Our findings are consistent with this previous literature and show that such attitudes are also relevant for a Lyme disease vaccine.
Although college students are an important population at risk for Lyme disease as they often engage in exercise in outdoor areas that places them at risk for Lyme disease in the high risk Lyme disease state of New York, this study has several limitations. First, participants surveyed were only from one college campus and this may not generalize to all college campuses. Second, as we surveyed college students, our data does not necessarily generalize to those above the age of 35. Future research should study other ages. Also, future research and public health recommendations should address the lack of performance of preventive behaviors for Lyme disease.
Conclusion
Engagement in Lyme disease preventive behaviors was low and there is a potential need for a Lyme disease vaccine. Asian/Asian American and South Asian race/ethnicities have strong interest in receiving a Lyme disease vaccine. There are a number of reasons why a Lyme disease vaccine would be useful. First, there are many regions where people are at risk for Lyme disease and this would be a vaccine of interest to consumers. Second, even for those who plan to engage in Lyme disease preventive behaviors, no one is perfect and people can miss detecting the tick that is attached to the human body and that can transmit Lyme disease. A vaccine would help address many of these missed ticks that can potentially infect humans. Third, many clinicians want to encourage their patients to engage in behaviors to prevent infection and disease. An approved vaccine would be something that clinicians could offer to their patients, especially for patients at high risk for exposure to ticks that can transmit Lyme disease. Also, although pharmaceutical companies may benefit by advertising a Lyme disease vaccine to Asian/Asian Americans and South Asians, marketers need to address and use approaches to interest those from other race/ethnicities. Also, marketers need to provide education to address the erroneous belief that vaccines are typically not safe in order to interest those with such beliefs to use a Lyme disease vaccine. In addition, pharmaceutical companies need to educate and work with clinicians to assure them that any approved Lyme disease vaccine is safe and efficacious and that clinicians should recommend such a vaccine to their patients.
Footnotes
Funding
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
Conflict of interest statement
The authors declare no conflicts of interest in preparing this article.